1. Field of the Invention
The present invention relates to an ophthalmic apparatus for measuring and analyzing refractive power distribution of an eye to be examined.
2. Description of Related Art
There is an apparatus known for measuring time-varying change in accommodative power of an eye (crystalline lens) to be examined. This type of apparatus measures eye refractive power varying with a fixation target, a gaze object, placed at far is moved closer to the eye, or the fixation target placed at near is moved farther from the eye.
However, this type of apparatus only measures eye refractive power of limited portions along specific meridian directions. Therefore, it is not capable of furnishing accommodative change of the eye (the crystalline lens) in detail.
The present invention has been made in view of the above circumstances and has an object to overcome the above problems and to provide an ophthalmic apparatus capable of furnishing accommodative change of the eye in detail.
Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the objects and in accordance with the purpose of the present invention, as embodied and broadly described herein, an ophthalmic apparatus comprises an input unit with which data on eye refractive power distribution of an eye to be examined at far vision, which is an unaccommodated state of the eye, and data on eye refractive power distribution of the eye at near vision, which is an accommodated state of the eye are inputted, a display, and a calculation and control unit which obtains data on distribution of difference between both the inputted data on distribution, so as to display at least one of the following data on the display: the data on the eye refractive power distribution at far vision; the data on the eye refractive power distribution at near vision; and the obtained data on the distribution of difference.
In another aspect of the present invention, an ophthalmic apparatus comprises a projecting optical system for projecting a measurement target on a fundus of an eye to be examined, a detecting optical system for detecting an image of the measurement target formed on the fundus, a target presenting optical system for presenting a target to the eye at a variable distance, a display, a and calculation and control unit which obtains data on eye refractive power distribution over each portion of a cornea of the eye based on results detected by the detecting optical system, and further obtaining data on distribution of difference between the data on eye refractive power distribution that have been obtained with the target presented at different distances, so as to display at least the obtained data on the distribution of difference.